Macrocyclic ketones having from 9 to 18 carbon atoms are useful as intermediates for medicines as well as perfumes or bases for perfumes.
For preparation of macrocyclic ketones, a method of cyclizing a diester of a linear alkanedicarboxylic acid by acyloin condensation reaction followed by reducing the thus cyclized intermediate has been proposed (Helv. Chem. Acta., 30, 1741 (1947)). The macrocyclic ketones obtained by the said method as a final reaction product are colored in yellow and have a weak irritant odor as these are, and therefore the musky smell is weak as being effaced by the said bad odor and these could not satisfy the quality required of perfumes, etc. Accordingly, the macrocyclic ketones were hitherto purified by distillation under reduced pressure and recrystallization (V.V. Dhekne et al., Indian J. Chem., 4, 524).
However, in order to improve the property of the macrocyclic ketones to such a degree that the ketones may be free from the coloration and bad odor for practical use by the purification process comprising the repetition of the above-mentioned distillation under reduced pressure and recrystallization, the number of the times of the repetition of the distillation and recrystallization is required to be increased, and as a result, the operation is complicated and the yield is poor. Thus the process is economically problematic.